<?php
/**
 * @version   1.6 October 30, 2011
 * @author    RocketTheme http://www.rockettheme.com
 * @copyright Copyright (C) 2007 - 2011 RocketTheme, LLC
 * @license   http://www.gnu.org/licenses/gpl-2.0.html GNU/GPLv2 only
 *
 *
 *
 * Original Author and Licence
 * @author Mateusz 'MatheW' Wójcik, <mat.wojcik@gmail.com>
 * @link http://mwojcik.pl
 * @version 1.0
 * @license GPL
 */

class RTCacheDriverFile implements RokCommon_Cache_Driver
{

    const DEFAULT_LIFETIME = 900;
	/**
	 * Directory with ending slash!
	 *
	 * @var string
	 */
	protected $dir = 'cache/';

	/**
	 * Extension of cache file - with comma!
	 *
	 * @var string
	 */
	protected $ext = '.cache';

    protected $lifeTime = self::DEFAULT_LIFETIME;

    protected $_locking = true;


	/**
	 * Constructor
	 *
	 * @throws RokCommon_Cache_Exception
	 * @param string $dir Directory - with ending slash!
	 */
	public function __construct($lifeTime=self::DEFAULT_LIFETIME, $dir=NULL)
	{
        $this->lifeTime = $lifeTime;
		if(!empty($dir) && $this->checkDirectory($dir)) $this->dir=$dir;
		else if(!$this->checkDirectory($this->dir)) throw new RokCommon_Cache_Exception('Unable to use given directory. Check file permissions.');
	}

    /**
     * Sets the lifetime of the cache
     *
     * @abstract
     * @param  int $lifeTime Lifetime of the cache
     * @return void
     */
    public function setLifeTime($lifeTime)
    {
        $this->lifeTime = $lifeTime;
    }       

	/**
	 * Sets data to cache
	 *
	 * @param string $groupName Name of group of cache
	 * @param string $identifier Identifier of data
	 * @param mixed $data Data
	 * @return boolean
	 */
	public function set($groupName, $identifier, $data){
		if(!$this->checkDirectory($this->createPath($groupName))) return false;
        $written	= false;
		$path		= $this->createPath($groupName, $identifier);
		$die		= '<?php die("Access Denied"); ?>'."\n";

		// Prepend a die string

		$data		= $die.$data;

		$fp = @fopen($path, "wb");
		if ($fp) {
			if ($this->_locking) {
				@flock($fp, LOCK_EX);
			}
			$len = strlen($data);
			@fwrite($fp, $data, $len);
			if ($this->_locking) {
				@flock($fp, LOCK_UN);
			}
			@fclose($fp);
			$written = true;
		}

		// Data integrity check
		if ($written && ($data == file_get_contents($path))) {
			return true;
		} else {
			return false;
		}
	}

	/**
	 * Gets data from cache
	 *
	 * @param string $groupName Name of group
	 * @param string $identifier Identifier of data
	 * @return mixed
	 */
	public function get($groupName, $identifier){

        if(time() - $this->modificationTime($groupName, $identifier) > $this->lifeTime){
            $this->clearCache($groupName, $identifier);
            return false;
        }
        $data = false;
		$path =$this->createPath($groupName, $identifier);
		if (file_exists($path)) {
			$data = file_get_contents($path);
			if($data) {
				// Remove the initial die() statement
				$data	= preg_replace('/^.*\n/', '', $data);
			}
		}
		return $data;
	}

	/**
	 * Clears cache of specified identifier of group
	 *
	 * @param string $groupName Name of group
	 * @param string $identifier Identifier
	 * @return boolean
	 */
	public function clearCache($groupName, $identifier){
		@unlink($this->createPath($groupName, $identifier));
	}

	/**
	 * Clears cache of specified group
	 *
	 * @param string $groupName Name of group
	 * @return boolean
	 */
	public function clearGroupCache($groupName){
		$this->deleteDir($this->createPath($groupName));
	}

	/**
	 * Clears all cache generated by this class with this driver
	 *
	 * @return boolean
	 */
	public function clearAllCache(){
		$this->deleteDir($this->dir, true);
	}



	/**
	 * Gets last modification time of specified cache data
	 *
	 * @param string $groupName Name of group
	 * @param string $identifier Identifier
	 * @return int
	 */
	public function modificationTime($groupName, $identifier){
		return filemtime($this->createPath($groupName, $identifier));
	}

	/**
	 * Check if cache data exists
	 *
	 * @param string $groupName Name of group
	 * @param string $identifier Identifier
	 * @return boolean
	 */
	public function exists($groupName, $identifier){
		return is_file($this->createPath($groupName, $identifier));
	}


	/**
	 * Sets cache directory
	 *
	 * @param string $dir Path to directory - with ending slash!
	 * @return void
	 */
	public function setDirectory($dir)
	{
		if($this->checkDirectory($dir)) $this->dir=$dir;
		else return false;
		return true;
	}

	/**
	 * Sets cache file extension
	 *
	 * @param string $ext File extension
	 */
	public function setExtension($ext)
	{
		$this->ext=$ext;
	}

	/**
	 * Check directory if it exists and is writable. It tries to create directory and give it good permissions
	 *
	 * @param string $dir
	 * @return boolean
	 */
	protected function checkDirectory($dir){
		if(!is_dir($dir) && mkdir($dir, 0777)==false) return false;
		if(!is_writable($dir) && chmod($dir, 0777)==false) return false;
		return true;
	}

	/**
	 * Deletes directory with content
	 *
	 * @param string $dir Path to directory with ending slash
	 * @param boolean $contentOnly
	 */
	protected function deleteDir($dir, $contentOnly=false){
		if ( ! $currentDir = @opendir($dir))
		return;

		while(FALSE !== ($fileName = @readdir($currentDir)))
		{
			if ($fileName != "." && $fileName != "..")
			{

				if (is_dir($dir.$fileName))
				{
					$this->deleteDir($dir.$fileName.'/');
				}
				else
				{
					@unlink($dir.$fileName);
				}
			}
		}
		@closedir($currentDir);

		if(!$contentOnly) @rmdir($dir);
	}

	/**
	 * Creates path to file/directory
	 *
	 * @param string $groupName
	 * @param string $identifier
	 * @return string
	 */
	protected function createPath($groupName, $identifier=NULL){
		return $this->dir.$groupName.'/'.(empty($identifier)?'':$identifier.$this->ext);
	}

} /* end of class FileRTCacheDriver */

?>